The best fiction illuminates life’s realities, and Stuart Nadler spotlights the fact that we all skate on a very thin edge between joy and sorrow, respectability and shame, life and death.

Or, as Henrietta tells her granddaughter, Lydia, in “The Inseparables,” you can be sitting next to a window in a restaurant having a perfectly nice lunch and, “A bird could come through the window right at this instant and impale you.”

One of the defining events of Henrietta’s life was writing a book, which “had in it the first in-depth diagram of the vagina that had ever appeared in a mainstream book, or, more accurately, a book that was being sold in the supermarket.” Think “Valley of the Dolls” mashed up against “The Joy of Sex.”

Henrietta intended it as a feminist statement that was “supposed to symbolize some epochal generational shift. Women assuming some whiff of a man’s primal violence.”

The book and its author were misunderstood. It sold well, but the book was roundly mocked and made its author infamous. In private, men assumed the author of a racy book would be sexually promiscuous.

Nadler’s novel examines the predatory sexual environment America’s daughters confront as they explore the jagged terrain of early adulthood. Here, it’s Lydia who becomes the prey.

When she was very young, Lydia was tucked in for the night on Sleeping Beauty bedsheets, and marinated in the fairy-tale notion that the kiss of a handsome prince would wake her up to a happily ever after. Henrietta had warned against buying the princess myths: “Dynastic power, jewel worship, the reanimating capacities of Prince Charming’s lips -- none of this will help you.”

At boarding school, Lydia’s boyfriend pressures her to send him a nude photo. She can’t believe he’s interested in her, but he pursues her romantically while badgering her for the photo. Lydia wonders just what it is that he sees and takes a picture of herself in the shower, but never sends it. The boy takes her phone and finds the photo. Soon the entire school has access.

At school, “being naked was cause enough to endure a hellacious amount of harassment. Forget the strenuously constructed veneer of high culture this school prided itself on: the instant her (body) began popping up on people’s phones all hell had broken loose for her.”

School administrators overlook the fact Lydia has been victimized. She is branded with a digital scarlet letter that discounts “whatever academic or personal currency or dignity a person might have earned by, say being alive.”

Oona, Lydia’s mother, can’t protect her daughter from this, nor can Lydia’s dad. He was once an involved father, filling in the gaps that Oona’s career as an orthopedic surgeon inevitably made in family life. Now he’s just mostly stoned.

Lydia is sent home on a two-week suspension and meets Oona’s new boyfriend. He overhears Lydia on the phone, yelling at the boy for ruining her life, and says, “You need to know that this is a kind of ritualistic male impulse to tear the female down.” He assures her the boy will one day outgrow it.

Meanwhile, Henrietta is packing up the house she shared with her late husband. She has agreed to republish the book she detests because she needs money and the publisher expects the reissue to be a big seller.

As Lydia’s crisis evolves, Oona remembers how wonderful it was to be a mother during “the oblivious years.” “Her baby had reminded her the world really was a wonderful and glorious place.” But nothing is permanent, and the seamier side of American culture cannot be kept at bay forever.

While Lydia navigates injustice and shame, Oona deals with the death of her marriage. And Henrietta is sifting through the artifacts of her late husband, “the drawers full of things that were once probably indispensable” to him, and she is beginning to comprehend the mistakes of treasuring possessions and career, and of grasping onto illusions that are, in the end, not worth anything at all.

For all the serious topics this book tackles, Nadler takes a light tone. He doesn’t preach; he reveals. (TNS)